1. Field of the Invention
The invention relates generally to tread plates and stair nosing structures as used in walkways, stairways and the like and, more particularly, but not by way of limitation, it relates to an improved manufacture of tread plate which utilizes a phosphorescent and highly wear-resistant composition of matter in affixure on the plate. 2. Description of the Prior Art
The prior art includes various types of tread plate that are adapted in many ways for affixure to a stair or walkway surface and such prior devices have been constructed from differing materials as dictated primarily by the exigencies of the application. There is a relative paucity of prior teachings that relate to such tread plate materials that also include a substance or attachment for visual aid. U.S. Pat. No. 4,058,942 teaches a flexible tread strip that includes fluorescent layers embedded in the upper surface. This structure is made from a wear-resistant resin such as urethane or polyamide with portions of flexible resin such as vinyl chloride. Fluorescent material strips are then formed of transparent synthetic resin sheet having a so-called fluorescent pigment blended therein. U.S. Pat. No. 3,421,274 is of interest as it is directed to a basic form of stair nosing structure which includes a transverse channel design for receiving a non-slip overlay material such as silicon carbide or aluminum oxide grit embedded or cast in epoxy, resin or the like. This patent includes no visual aid material or structure.